Inertially-actuated taillight system

ABSTRACT

Vehicle taillight apparatus for indicating changes in vehicle speed. The taillight assembly includes a continuously energized lamp and first and second lenses fixedly secured to the vehicle so the lenses transmit light from the lamp rearwardly of the vehicle. A screen assembly including a first screen having a central aperture and a second screen having colored sections is slidably positioned between the lamp and the first lens so only light passing through the aperture strikes the first lens and only light passing through a colored section strikes the second lens. The screen assembly is biased to a certain position so inertial forces on the screen assembly due to vehicle acceleration and deceleration move the screen sufficient to vary the amount of light emanating from the first lens and the color of light emanating from the second lens. The taillight assembly also includes a brake switch actuated electromagnet for moving the screen assembly to a position indicative of maximum deceleration whenever the vehicle brakes are applied.

Jacobs July 24, 1973 INERTIALLY-ACTUATED TAILLIGHT SYSTEM PrimaryExaminer-John W. Caldwell Assistant Egcaminer-Kenneth N. Leimer [75]Inventor: James q Dayton ohm AttorneyJ L. Carpenter and Paul Fitzpatrick[73] Assignee: General Motors Corporation,

Detroit, Mich. 57 ABSTRACT [22] Filed: Aug. 23, 1971 Vehicle taillightapparatus for indicating changes in vehicle speed. The taillightassembly includes a continu- [21] Appl' 173315 I ously energized lampand first and second lenses fixedly secured to the vehicle so the lensestransmit light from [52] U.S. Cl 340/71, 116/42, 240/83, the lamprearwardly of the vehicle. A screen assembly 340/66, 340/122, 340/262including a first screen having a central aperture and a [51] Int. ClB60q 1/44 second screen having colored sections is slidably posi- [58]Field of Search 340/71, 72; 116/28, tioned between the lamp and thefirst lens so only light 116/35-38, 42-45, 50, 56; 240/4603, 46.05passing through the aperture strikes the first lens and only lightpassing through a colored section strikes the [56] References Citedsecond lens. The screen assembly is biased to a certain UNITED STATESPATENTS position so inertial forces on the screen assembly due 1,330,5622/1920 Wakefield 116/42 vehicle .cceleratm and decele'atlm t 2 249 7857/1941 Roper et aL 240/4603 screen sufficient to vary the amount oflight emanating 1:7 :51 12 1930 Chambers 40 4 05 X from the first lensand the C010! 0f light emanating from 1,863,688 6/1932 Delmas 116/42 thesecond lens- The taillight assembly also includes 8 3,296,998 1/1967Kirk 116/28 R brake switch actuated electromagnet for moving the FOREIGNPATENTS OR APPLICATIONS screen assembly to a position indicative ofmaximum 1 deceleration whenever the vehicle brakes are applied. 577,2816/1924 France 240/4603 1,014,504 12/1965 Great Britain 340/71 3 Chums, 9Dl'lwlng Figures i8 7 r 28 i 2 M 52 Z ,6 I\ t I I I H l I k \l// n n 4844 a) I? o :'3 55 l w za- 1 E I a '1 Patented July 24, 1973 2Sheets-Sheet 1 Patented July 24, 1973 3,748,643

2 Sheets-Sheet 2 BY QEzmes "(Jacobs AUORNEY INERTIALLY-ACTUATEI)TAILLIGHT SYSTEM This invention relates to vehicle taillight systemsand, more particularly, to taillight apparatus which provides thefunction of a continuously energized taillight and which also indicatesspeed changes of the vehicle to which the taillight apparatus isattached.

Most modern automobiles have taillights which are continuously energizedso as to indicate the presence of a vehicle in darkness and to provideincreased light intensity when the vehicle is being braked, whichadvises following motorists of the vehicle deceleration. While variousother vehicle taillight systems have been proposed in which speedchanges of the vehicle are in dicated to following motorists regardlessof whether the vehicle brakes are applied, these other systems have notgained widespread acceptance. The reason for this situation is thoughtto be that, while under certain circumstances it would be to theadvantage of motorists following a vehicle to be advised of speedchanges in the vehicle, following motorists who are unfamiliar with thesignalling system of the vehicle in question may be confused by such asystem. Since this element of possible confusion has been felt tooutweigh the advantages of such a signalling system, the future use ofsuch systems remains unforeseeable and the search for such a systemwhich would minimize the possibility of driver confusion continues.Before progressing further with this description it should be noted thatthe terms acceleration and deceleration it contains refer to a time rateof change in the forward speed of a vehicle. Of course, persons versedin the art will appreciate that deceleration is actually negativeacceleration and vice versa.

It is, therefore, an object of this invention to provide taillightapparatus which indicates speed changes of a vehicle by varying theilluminatedarea of a lens which is continuously illuminated by a lamp.

It is also an object of this invention to provide taillight apparatusfor indicating changes in the speed of a vehicle by movement of anacceleration responsive multiple colored screen between a lens and acontinuously energized lamp in response to vehicle speed changes.

It is an additional object of this invention to provide a taillightassembly which incorporates continuously illuminated taillight lensesand which both varies the illuminated area of a first lens and alsovaries the color of light emanating from a second lens as an indicationof vehicle speed changes.

It is yet another object of this invention to provide a taillightassembly in which an acceleration responsive element effects anindication of vehicle speed changes and in which apparatus responsive toapplication of the vehicle brakes causes the acceleration responsiveelement to effect an indication of maximum deceleration of the vehicleregardless of actual deceleration of the vehicle whenever the vehiclebrakes are applied.

It is yet a further object of this invention to provide a vehicletaillight assembly in which a single lamp is continuously energized toeffect illumination of inner and outer concentric lenses of differentdiameters, the illuminated area of the inner lens and the color of lightilluminating the outer lens being varied to indicate speed changes ofthe vehicle.

The foregoing and other objects and advantages of the subject inventionwill become apparent from the accompanying description and drawings, inwhich:

FIG. 1 is a sectional view of vehicle taillight apparatus incorporatingthe principles of the subject invention;

FIG. 2 is a plan view of an acceleration responsive element incorporatedin the apparatus of FIG. 1;

FIGS. 3 through 5 are sectional views of the taillight assemblydisclosed in FIG. 1 under various conditions of acceleration; and

FIGS. 6 through 9 are elevation views of the lenses employed in thetaillight assembly of FIG. 1 as they are illuminated when the vehicle isunder various conditions of acceleration.

As shown in FIG. 1, vehicle taillight apparatus according to theprinciples of the subject invention includes a taillight assembly 10, apower source, such as a vehicle battery 12, a switch 14 for energizingthe taillight assembly 10, and a brake switch 16 for controlling theindications provided by the taillight assembly 10 in accordance withapplication of the vehicle brakes. Persons versed in the art willappreciate that many diverse and well-known types of switches may beemployed as the switches 14 and 16 so theyare only schematicallyillustrated for purposes of this description. By way of example, andwithout limitation, the brake switch 16.

may be a conventional normally open brake switch that is closed when thevehicle brakes are applied and the switch 14 may be included in amultiple pole, multiple throw switch employed to control energization ofthe vehicles ignition system. When so employed the switch 14 would beclosed whenever the vehicle is in operation.

In the illustrated embodiment the taillight assembly 10 includes anelectrically grounded housing 18 which is connected to the vehicle (notshown) and supports a lamp assembly 20 for generating light. Thetaillight assembly 10 also includes first and second concentric lenses22 and 24 for transmitting light from the lamp assembly 20 rearward ofthe vehicle, an acceleration responsive screen assembly 26 for detectingspeed changes of the vehicle and for controlling the illumination of thelenses 22 and 24 by the lamp assembly 20 in accordance with vehiclespeed changes, first and second springs 28 and 30 for biasing the screenassembly 26 to a certain position when the vehicle is not undergoingacceleration, and a solenoid 32 having a magnetic core 33 forcontrolling the position of the screen assembly 26 when application ofthe vehicle brakes (not shown) effects closure of the normally openbrake switch 16.

In the illustrated embodiment the lamp assembly 20 includes a lamp 34having a metal base 36 that is positioned within a socket 38 formed inthe housing 18. Accordingly, the base 36 serves as an electricallygrounded contact of the lamp 34 while a second contact 40 of the lamp 34is electrically connected to the battery 12 through a pin 42 and theignition switch 14. The pin 42 is electrically isolated from the housing18 by an insulating grommet 44 that also isolates a second pin 46 fromthe housing 18, the second pin 46 serving as an electrical tenninal forconnection of the solenoid 32 to the battery 12 through the brake switch16. The magnetic core 33 of the solenoid 32 is secured to the screenassembly 26, as through use of an adhesive, for purposes soon to bedescribed. Since the lamp 34 is connected to the battery 12 whenever theignition switch 14 is closed the lamp 34 serves as a taillight wheneverthe vehicle is in operation and the light which it generates illuminatesthe lenses 22 and 24 through the screen assembly 26.

The screen assembly 26, as shown in FIGS. 1 and 2, includes a firstscreen 48 of an opaque material defining an aperture 50 through whichlight passes from the lamp 34 to the first lens 22. The screen assembly26 also includes a second screen 52 for controlling the color of lightentering the second lens 24 from the lamp 34. The second screen 52includes a substantially cylindrical support member 54 of a transparentmaterial on which are disposed cylindrical sections 56 through 59 ofcolored translucent material, the colors of which will subsequently bedescribed. The screen assembly 26 also includes a spring retainer 60 forretaining the second spring 30 in a position concentric with the lamp 34and for supporting the magnetic core 33. The first screen 48 serves as aspring retainer for the first spring 28 which, together with the secondspring 30, biases the screen assembly 26 to a certain position withinthe cylindrical bore 62 that is formed by the lenses 22 and 24.Accordingly, the position of the screen assembly 26 within the bore 62is determined by the compressive forces in the springs 28 and 30, whichforces vary as the vehicle accelerates and decelerates.

As persons versed in the art will appreciate, the inertia of the screenassembly 26 causes it to resist changes in its speed. Since it may beassumed that friction within the bore 62 is negligible, the accelerationof the housing and the screen assembly 26 can only be equal when theforces in the springs 28 and 30 are unbalanced sufficiently toaccelerate the screen assembly 26 at the same rate as the housing 10 isaccelerated by the vehicle. For purposes of this description, theseunbalanced forces will be termed inertial forces since they are causedby the need to overcome the inertia of the screen assembly 26. I

The operation of the subject apparatus will now be explained inconjunction with the remaining FIGS. 3-9. When the speed of the housing18, which is rigidly attached to the vehicle, is constant, there are noinertial forces on the screen assembly 26 so it is held in the positionillustratedin FIG. 1 by the springs 28 and 30. Under these conditionslight from the lamp 34 shining through the aperture 50 of the firstscreen 48 illuminates a moderately large central portion of the firstlens 22. By making the lens 22 of a red transparent or translucentmaterial, such as the familiar materials presently used in vehicletaillights, motorists following the taillight assembly 10 will observe ared light shining from the central portion of the first lens 22.

In addition, when the vehicle speed is constant motorists following thevehicle are able to observe light emanating from the second lens 24after the light has passed from the lamp 34 through the support member54 and the section 57 of the second screen 52. While the materialsemployed in the taillight assembly 10 need not be limited to particularcolors or substances, it is contemplated in the preferred embodimentthat the support member 54 and the second lens 24 are made of a cleartransparent or translucent plastic and that the sections 56 through 59of the second screen 52 are made of various colored cylindrical sectionsof transparent or translucent plastic, the sections 56 through 59 beingcolored green, yellow, red on white, and red, respectively. It is thusapparent that the color of light emanating from the second lens 24 willbe the same as the color of the plastic through which it passes on thesecond screen 52. Accordingly, when the vehicle speed is constant thelight which emanates from the second lens 24 is yellow in color due toits passage through the yellow section 57 of the second screen 52.Motorists following the taillight assembly 10 under these conditionsthus view the taillight assembly 10 as being a moderately large redcircle of light within a surrounding ring of yellow light, as shown inFIG. 6.

Should the vehicle carrying the taillight assembly 10 be accelerated ina forward direction the resulting inertial forces on the screen assembly26 cause it to shift rearwardly in the bore 62, as shown in FIG. 3. Theresulting translation of the screen assembly 26 relative to the lamp 34and the first lens 22 causes a decrease in the area of the first lens 22which is exposed to the lamp 34 through the aperture 50. In addition,the movement of the second screen 52 when the vehicle is acceleratedaligns the green section 56 of the second screen 52 with the lamp 34 andthe second lens 24 so that light emanating from the second lens 24 isgreen in color. Accordingly, when the vehicle is accelerating followingmotorists view the taillight assembly 10 as a relatively small redcircle of light surrounded by a green ring of light, as shown in FIG. 7.

Should the vehicle be decelerated at a moderate rate without applyingthe vehicle brakes, as may be effected merely by releasing the vehicleaccelerator, the resulting inertial forces on the screen assembly 26cause it to shift forward, as shown in FIG. 4. Under these conditionsthe aperture 50 in the first screen 48 exposes a greater than normalamount of the first lens 22 to the lamp 34 and the red on white section58 of the second screen 52 is aligned with the lamp 34 and the secondlens 24. Accordingly, motorists following the taillight assembly 10under these conditions view the taillight assembly 10 as being a largered circle surrounded by a ring of light having red and white sectionssubstantially as illustrated in FIG. 8. It should also be noted that, byarranging the red and white portions of the red on white section 58 asillustrated in FIG. 2, minor variations in the vehicle deceleration ratewill so change the inertial forces on the screen assembly 26 and varythe portion of the section 58 through which light passes to the secondlens 24 as to effect a flashing of the red and white areas of lightemanating from the second lens 24. This flashing light further serves toadvise following motorists that the vehicle equipped with the taillightassembly 10 is being decelerated.

Should the vehicle equipped with the taillight assembly 10 be rapidlydecelerated without application of the vehicle brakes, such as during adeceleration caused by downshifting the vehicle transmission, theincreased inertial forces on the screen assembly 26 cause it to shift toits forwardmost position relative to the housing 18, as shown in FIG. 5.Under these conditions the first screen 48 is shifted so far forward asto expose the env tire end surface of the first lens 22 to the lamp 34through the aperture 50. In addition, the rapid deceleration of thevehicle causes the red section 59 of the second screen 52 to be alignedwith the lamp 34and the second lens 24 so that light emanating from thesecond lens 24 is red in color. Accordingly, when the vehicle is rapidlydecelerated the taillight assembly 10 appears to following motorists asa single very large red light inasmuch as the light from each of thelenses 22 and 24 is red in color, as shown in FIG. 9.

Since the rate of deceleration of the vehicle equipped with thetaillight assembly may be rapidly increased while the vehicle brakes areapplied merely by increasing pressure on the vehicle brake pedal, it isbelieved desirable that following motorists be given the sameinformation whenever the vehicle is being braked as they are given whenthe vehicles deceleration rate is at a maximum. Accordingly, wheneverthe vehicle is being braked the brake switch 16 is closed'so as toenergize the solenoid 32. Upon energization of the solenoid 32 themagnetic core 33, which is securedto the screen assembly 26, is drawninto the solenoid 32, as shown in FIG. 5, so long as the brake switch 16is closed. Ac-

cordingly, whenever the brakes of the vehicle are applied the screenassembly 26 is shifted to the same position it assumes when the vehicleis undergoing maximum rates of deceleration, as portrayed in FIG 5.Motorists following the vehicle thus view the taillight assembly 10 as asingle large red light, shown in FIG. 9, whenever the vehicle brakes areapplied regardless of the actual vehicle deceleration.

While the foregoing description has been directed toward operation ofthe vehicle in a forward direction, persons versed in the art willappreciate that the taillight assembly 10 is also responsive toacceleration and deceleration of the vehicle in a rearward direction.For example, when the vehicle accelerates in a rearward direction theresulting inertial forces on the screen assembly 26 shift it in aforward direction so as to provide the aforedescribed full redindication of FlG. 9 or the flashing indication of FIG. 8, depending onthe rate of acceleration. Similarly, rearward deceleration will causethe display presented in FIG. 7.

Though the foregoing description has been directed toward'theillustrated and preferred embodiment of the subject invention, personsversed in the art will appreciate that various modifications of thisinvention may be made without departing from its spirit.

What is claimed is:

1. Apparatus for indicating changes in the speed of a vehiclecomprising, in combination, a light source for generating light, firstand second lenses forreceiving and transmitting light emanating from thelight source, an opaque screen having an aperture positioned between thelight source and the first lens for limiting the area of the first lensexposed to light emanating from the light source, a second screenpositioned between the light source and the second lens, the secondscreen having a plurality of diverse colored substantially transparentsections and being adapted for translational movement so as toselectively align each of the sections with the light source and thesecond lens as the screen is moved, and means for moving the screensrelative to the light source in response to changes in the speed of thevehicle whereby the area of the first lens that is exposed to light fromthe light source and the color of the screen section that is positionedbetween the light source and the second lens are varied in response toacceleration and deceleration of the vehicle, the area of lightemanating from the first lens and the color of light emanating from thesecond lens thereby indicating whether the vehicle speed is constant,increasing, or decreasing.

2. Vehicle taillight apparatus comprising, in combination, a lamprigidly secured to the rear of the vehicle for continuously generatinglight, a first lens fixedly positioned relative to and rearward of thelamp effective to transmit light from the lamp rearward of the vehicle,an opaque screen having an aperture movably positioned between the lampand the first lens for varying the area of the first lens exposed tolight from the lamp, a second lens positioned proximate the first lensand effective to transmit light from the lamp rearward of the vehicle, asecond screen positioned between the lamp and the second lens, thesecond screen being adapted for translational movement and having aplurality of light transmitting sections of diverse colors, means forbiasing the first and second screens to respective predeterminedpositions when the vehicle speed is constant so as to expose a certainarea of the first lens to light from the lamp and to align apredetermined section of the second screen with the lamp and the secondlens, and means responsive to acceleration and deceleration of thevehicle for effecting translation of the first screen relative to thelamp and the first lens so as to vary the area of the first lens exposedto light from the lamp in response to vehicle speed changes andeffecting translation of the second screen so as to change the sectionof the second screen that is aligned with the lamp and the second lensin response to vehicle speed changes whereby both the color of lighttrans mitted rearward of the vehicle by the second lens and the area ofthe first lens that transmits light rearward of the vehicle are variedin response to speed changes of the vehicle.

3. A vehicle taillight assembly for indicating acceleration,deceleration, and braking of the vehicle comprising, in combination, alamp fixedly attached to the vehicle for continuously generating light,a first lens of a certain color fixedly positioned relative to the lampand oriented to receive light from the lamp and to transmit light of thecertain color rearwardly of the vehicle, a screen having an aperturepositioned between the lamp and the lens for limiting the area of thefirst lens exposed to light from the lamp to that area which is alignedwith the aperture and the lamp, the screen being adapted for movementbetween the lens and the lamp, biasing means for biasing the screen to acertain position when the vehicle speed is constant and for effectingtranslation of the screen between the lamp and the first lens when thespeed of the vehicle is being changed, the inertia of the screen whenthe vehicle decelerates moving the screen toward the lamp so as toincrease said area and, when the vehicle accelerates, moving the screentoward the first lens so as to decrease said area, said area and theamount of light transmitted by the first lens thereby being varied inresponse to acceleration and deceleration of the vehicle, asubstantially annular lens positioned so as to substantially surroundand be concentric with the first lens to receive light from the lamp andto transmit light rearwardly of the vehicle, a substantially cylindricalscreen having a plurality of colored light transmitting substantiallycylindrical sections positioned between the annular lens and the lamp,the sections each being selectively alignable with the lamp and theannular lens so that light from the lamp passes through one of thesections to the annular lens, means for securing the cylindrical screento the apertured screen for translational movement therewith so as tovary the color of light entering the annular lens in response toacceleration and deceleration of the vehicle whereby light entering theannular lens from the lamp passes through a certain section of thecylindrical screen when the speed of the plication of the vehicle brakesfor indicating deceleration of the vehicle by moving the screens totheir forwardmost position when the vehicle brakes are applied regardlesI 3 3 2 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,748,643 Dated July 24, 1973 Inventor(s) James W. Jacobs It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 8, line 4, "regardles" should be deleted and substituted thereforregardless of actual speed change of the vehicle, thereby increasingsaid area to a maximum and aligning a section rearward of the certainsection with the lamp and the annular lens whenever the vehicle brakesare applied. a a

Signed and sealed this 19th day of March 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents

1. Apparatus for indicating changes in the speed of a vehiclecomprising, in combination, a light source for generating light, firstand second lenses for receiving and transmitting light emanating fromthe light source, an opaque screen having an aperture positioned betweenthe light source and the first lens for limiting the area of the firstlens exposed to light emanating from the light source, a second screenpositioned between the light source and the second lens, the secondscreen having a plurality of diverse colored substantially transparentsections and being adapted for translational movement so as toselectively align each of the sections with the light source and thesecond lens as the screen is moved, and means for moving the screensrelative to the light source in response to changes in the speed of thevehicle whereby the area of the first lens that is exposed to light fromthe light source and the color of the screen section that is positionedbetween the light source and the second lens are varied in response toacceleration and deceleration of the vehicle, the area of lightemanating from the first lens and the color of light emanating from thesecond lens thereby indicating whether the vehicle speed is constant,increasing, or decreasing.
 2. Vehicle taillight apparatus comprising, incombination, a lamp rigidly secured to the rear of the vehicle forcontinuously generating light, a first lens fixedly positioned relativeto and rearward of the lamp effective to transmit light from the lamprearward of the vehicle, an opaque screen having an aperture movablypositioned between the lamp and the first lens for varying the area ofthe first lens exposed to light from the lamp, a second lens positionedproximate the first lens and effective to transmit light from the lamprearward of the vehicle, a second screen positioned between the lamp andthe second lens, the second screen being adapted for translationalmovement and having a plurality of light transmitting sections ofdiverse colors, means for biasing the first and second screens torespective predetermined positions when the vehicle speed is constant soas to expose a certain area of the firsT lens to light from the lamp andto align a predetermined section of the second screen with the lamp andthe second lens, and means responsive to acceleration and decelerationof the vehicle for effecting translation of the first screen relative tothe lamp and the first lens so as to vary the area of the first lensexposed to light from the lamp in response to vehicle speed changes andeffecting translation of the second screen so as to change the sectionof the second screen that is aligned with the lamp and the second lensin response to vehicle speed changes whereby both the color of lighttransmitted rearward of the vehicle by the second lens and the area ofthe first lens that transmits light rearward of the vehicle are variedin response to speed changes of the vehicle.
 3. A vehicle taillightassembly for indicating acceleration, deceleration, and braking of thevehicle comprising, in combination, a lamp fixedly attached to thevehicle for continuously generating light, a first lens of a certaincolor fixedly positioned relative to the lamp and oriented to receivelight from the lamp and to transmit light of the certain colorrearwardly of the vehicle, a screen having an aperture positionedbetween the lamp and the lens for limiting the area of the first lensexposed to light from the lamp to that area which is aligned with theaperture and the lamp, the screen being adapted for movement between thelens and the lamp, biasing means for biasing the screen to a certainposition when the vehicle speed is constant and for effectingtranslation of the screen between the lamp and the first lens when thespeed of the vehicle is being changed, the inertia of the screen whenthe vehicle decelerates moving the screen toward the lamp so as toincrease said area and, when the vehicle accelerates, moving the screentoward the first lens so as to decrease said area, said area and theamount of light transmitted by the first lens thereby being varied inresponse to acceleration and deceleration of the vehicle, asubstantially annular lens positioned so as to substantially surroundand be concentric with the first lens to receive light from the lamp andto transmit light rearwardly of the vehicle, a substantially cylindricalscreen having a plurality of colored light transmitting substantiallycylindrical sections positioned between the annular lens and the lamp,the sections each being selectively alignable with the lamp and theannular lens so that light from the lamp passes through one of thesections to the annular lens, means for securing the cylindrical screento the apertured screen for translational movement therewith so as tovary the color of light entering the annular lens in response toacceleration and deceleration of the vehicle whereby light entering theannular lens from the lamp passes through a certain section of thecylindrical screen when the speed of the vehicle is constant, through asection forward of the certain section when the vehicle is accelerating,and through a section rearward of the certain section when the vehicleis decelerating, and means responsive to application of the vehiclebrakes for indicating deceleration of the vehicle by moving the screensto their forwardmost position when the vehicle brakes are appliedregardless of actual speed changes of the vehicle, thereby increasingsaid area to a maximum and aligning a section rearward of the certainsection with the lamp and the annular lens whenever the vehicle brakesare applied.